Plugin controller spec: Plugin routes are not drawn

Development
7

For who might experience the same problem as described above, one way I am able to get the routes drawn with an engine was defining the engine inside plugin.rb rather than lib/engine.rb.

after_initialize do
  # …

  module ::Plugin
    class Engine < ::Rails::Engine
      engine_name Plugin::PLUGIN_NAME
      isolate_namespace Plugin
    end
  end

  Plugin::Engine.routes.draw do
    get '/my_routes' => 'routes#index'
    put '/my_routes/:route_id' => 'routes#update'
    delete '/my_routes/:route_id' => 'routes#destroy'
  end

  Discourse::Application.routes.append do
    mount Plugin::Engine, at: '/plugin', constraints: AdminConstraint.new
  end
end

Why that makes any difference is beyond me.

As for the strategy that was suggested: Yes, I could certainly try re-implementing my plugin starting with one of the default plugins and observe at which point the described failure occurs. However, that’s very impractical as I’ve working on the plugin for close to a year.